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    <script>
        // 1.求1~100之间所有数的平均值
        var arg;
        var sum1 = 0;
        for (var i = 1; i <= 100; i++) {
            sum1 += i;
        }
        arg = sum1 / i;
        console.log(arg);

        // 2.求1~100之间所有偶数和奇数的和
        var even = 0;
        var odd = 0;
        for (var i = 1; i <= 100; i++) {
            if (i % 2 == 0) {
                even += i;
            } else {
                odd += i;
            }
        }
        console.log('偶数和为' + even);
        console.log('奇数和为' + odd);

        // 3.求1~100之间所有能被3整除的数字的和
        var sum2 = 0;
        for (var i = 1; i <= 100; i++) {
            if (i %3 == 0) {
                sum2 += i;
            }
        }
        console.log('能被3整除的数字和为：' + sum2);
    </script>
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